President Donald Trump says he's given Attorney General William Barr "total release" to probe the roots of the Russia probe that Trump repeatedly has called a "witch hunt."

"I gave him a total release, in other words, he's got everything, anything he needs, he's got it," Trump told Fox News host Sean Hannity Thursday night. "He is the attorney general of the United States, but he's got a lot of very good people under him that I guess are involved and I gave him a total release, so all of it has been released and he has all of it."

Trump added, "I've also given him authorization to release it to whoever he wants."

Trump authorized Barr in May to investigate the Russia probe investigators and their actions in the wake of special counsel Robert Mueller's report. Mueller, a former FBI director, found insufficient evidence that anyone on Trump's team conspired with the Russians to win the 2016 election. He did not make a decision on whether to pursue an obstruction of justice case against Trump, but Barr and then-Deputy Attorney General Rod Rosenstein opted not to move forward with a case.

Trump and his allies claim there was a conspiracy within the government, including at the FBI, to prevent Trump from serving as president by way of the Russia investigation — the origins of which are not entirely clear. Multiple FISA warrants were authorized in 2016 and 2017, which allowed the FBI to surveil some of Trump's advisers.

Mueller's Russia probe resulted in several criminal convictions, but none of them were related to conspiring with Russia or obstructing justice.

Mueller testified in front of two congressional committees this week, which the White House is framing as a victory for Trump.